JPS63315359A - Hydraulic pressure booster - Google Patents

Abstract

PURPOSE:To simplify the construction of a reaction mechanism for transmitting the reaction force of an output lever to a valve piston and enable easy machining by providing the mechanism near the rear end of a booster piston and between the booster piston and the valve piston. CONSTITUTION:A hydraulic pressure booster B has a booster cylinder 32 to be connected to the rear end of a master cylinder M, and a reaction mechanism R for transmitting the reaction force of an output lever 44 to a valve spindle 56 is provided between a booster piston 35 inserted in the booster cylinder 32 and a valve spindle 36 so inserted therein as to be freely shiftable in an axial direction. In this case, the reaction mechanism R is provided near the rear end of the booster piston 35 and between the booster piston 35 and the valve piston 56. And this reaction mechanism R comprises a cylindrical support member 69 surrounding the valve piston 56 and axially supported on a rod part 35c, and a transmission member 71 capable of contact with a collar part 70 extended from the rear end of the valve spindle 56 in a radial outward direction and supported on the support member 69.

Description

Detailed Description of the Invention A1 Objective of the Invention (1) Industrial Application Field The present invention provides a booster cylinder coupled to the rear end of the master cylinder, and a master piston slidably fitted into the master cylinder. A booster piston having an output rod at its tip that abuts the rear end is slidably fitted, and an output hydraulic chamber formed facing the back of the booster piston and an input hydraulic chamber communicating with a hydraulic pressure supply source are provided. , an inlet valve is interposed that opens in response to the forward motion of a valve piston inserted into the booster piston so as to be axially movable in series with the hill operation member, and an outlet chamber communicating with the output hydraulic chamber and the oil tank; An outlet valve is interposed between the booster piston and the valve piston, and a reaction mechanism is provided between the booster piston and the valve piston to transmit the operational reaction force of the output rod to the valve piston. The present invention relates to a hydraulic booster in which a hydraulic booster is provided.

(2) Conventional technology Conventionally, such hydraulic boosters have been used, for example, in Japanese Patent Application Laid-open No.
It is publicly known from Publication No. 191863 and the like.

(3) Problems to be Solved by the Invention In the above-mentioned conventional system, the reaction mechanism is provided between the tip of the valve piston and the output rod, and the reaction mechanism is disposed deep inside the hydraulic booster.

For this reason, the structure of the reaction mechanism has to be complicated due to the arrangement of the inlet valve, the outlet valve, etc., and therefore the processing has been complicated.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a hydraulic booster in which the structure of the reaction mechanism is simplified, and the processing thereof is thereby simplified.

B0 Structure of the Invention (1) Means for Solving Problems According to the present invention, the reaction mechanism is provided between the booster piston and the valve piston near the rear end of the booster piston.

(2) Effect According to the above configuration, the reaction mechanism is disposed at the rear end of the hydraulic booster and is unrelated to the inlet valve, Yamaguchi valve, etc., so the structure of the reaction mechanism is simplified. , processing can be made easier accordingly.

(3) Embodiment Below, an embodiment of the present invention will be explained with reference to the drawings. First, in FIG.
An oil tank 2 is formed above it. The lower part of the oil tank 2 is divided by a partition wall 3 into a front oil sump 4 and a rear oil sump 5.

The cylinder body 1 is provided with a cylinder hole 6 whose front end is closed. The portion 6b is successively provided with a step difference. The entire front master piston 7 and the front end portion of the rear master piston 8, that is, the small diameter piston portion 8a, are slidably fitted into the small diameter hole 6a, and the rear master piston 8 is fitted into the large diameter hole 6b. The rear end portion, that is, the large diameter piston portion 8b is slidably fitted. A front hydraulic chamber 9 is defined between the front end wall of the cylinder hole 6 and the front master piston 7, and a rear hydraulic chamber 10 is defined between the front master piston 7 and the rear master piston 8. A replenishment oil chamber 11 is defined between the small diameter piston portion 8a and the large diameter piston portion 8b of the rear master piston 8. Further, the front hydraulic chamber 9 accommodates a first return spring 12 that biases the front master piston 7 rearward, and the rear hydraulic chamber IO accommodates both master pistons 73.
8 in the direction away from each other, the first return spring 12
The second return spring 13 has a cent load smaller than that of the second return spring 13.
is accommodated. By these return springs 12, 13, both master pistons 7.8 move forward and backward in conjunction with each other.

The cylinder body 1 has a first cylinder which is always in communication with the front hydraulic chamber 9.
The output boat 14 and the second hydraulic chamber 14 are connected to the rear hydraulic chamber 10 at all times.
Output port 15 is drilled, and these output ports 1-1
4 and 15 are connected to hydraulic brake circuits (not shown), respectively. Therefore, each hydraulic brake circuit is supplied with brake hydraulic pressure depending on the pressurized state of the front hydraulic chamber 9 and the rear hydraulic chamber 10, respectively. In addition, the replenishment oil chamber 11 is
The rear oil sump 5 is
will be communicated to.

The front master piston 7 is provided with a pair of lands 18.19 spaced apart in the axial direction with an annular groove 17 interposed between them. A cup seal 20.21 is fitted in sliding contact with the inner surface, thereby defining an annular oil chamber 22 between both lands 18.19. Moreover, the front hydraulic chamber 9 and the oil chamber 22
The land 18 between and the cup seal 20 fitted to the land 18 allow hydraulic oil to flow from the oil chamber 22 to the front hydraulic chamber 9 when the pressure in the front hydraulic chamber 9 is lower than that of the oil chamber 22. The cylinder body 1 is provided with an oil hole 23 that communicates the oil chamber 22 with the front oil reservoir 4.

At the front of the front master piston 7, there is a valve mechanism 25 that is driven to open and close by a stopper bolt 24 that passes through the histone 7 on one diameter line and is fixed to the cylinder body 1. The chambers 22 are arranged so as to be able to communicate with each other and shut off, and the valve mechanism 25 is pressed by the stopper bolt 24 to open the valve when the front master piston 7 returns to the retraction limit. The front master piston 7 has a long hole 26 extending along one diameter line between both lands 18 and 19.
is bored, and the stopper bolt 24 is inserted into the long hole 26.
inserted into.

At the front end portion of the rear master piston 8, that is, the small diameter piston portion 8a, there is a cup seal 2 that slides into contact with the inner surface of the small diameter hole portion 6a.
7 is attached, and this cup seal 27 and small diameter piston part 8a prevent the flow of hydraulic oil from the replenishment oil chamber 11 to the rear hydraulic chamber 11 when the pressure in the rear hydraulic chamber IO is lower than that of the replenishment oil chamber 11. Constructed to allow. Further, in the cylinder body 1, an oil passage 16 and a rear hydraulic chamber 10 are provided which work together with a cup seal 27 as the rear master piston 8 moves back and forth.
A relief hole 28 is drilled to provide communication/blocking between the oil passage 16 and the rear hydraulic chamber 10 when the rear master piston 8 returns to the retraction limit.

Referring also to FIG. 2, a booster cylinder 32 of a hydraulic booster B is coaxially connected to the rear end of the cylinder body l of the master cylinder M with a guide ring 31 interposed therebetween. Booster cylinder 32 is connected by bolt 33.

Here, the diameter of the small diameter hole 6a in the cylinder hole 6 is DI
, the diameter of the large-diameter hole 6b is D2, the inner diameter of the guide ring 31 is 1, and the diameter of the cylinder hole 34 in the booster cylinder 32 is D4, and these are set in the following relationship.

Dr <Di <D, <02 The cylinder hole 34 of the booster cylinder 32 has a large diameter piston portion 35a provided at the rear of the booster piston 35.
are slidably fitted. The front portion of the pusher piston 35 is formed as a small diameter piston portion 35b, and the small diameter piston portion 35b is slidably fitted into the guide ring 31.

Further, at the rear of the booster piston 35, a rod portion 35c is provided.
are coaxially protruded, and this rod portion 35c penetrates the rear end wall of the booster cylinder 32 in an oil-tight manner and projects rearward. Further, the cylinder hole 34 is provided with a stepped portion 36 that can come into contact with the rear end surface of the large-diameter piston portion 35a in order to define the retraction limit of the booster piston 35.

By inserting the booster piston 35 into the cylinder hole 34 in this way, the cylinder hole 34 and the booster piston 35 are connected between the guide ring 31 and the large diameter piston portion 35a.
An annular input hydraulic chamber 37 is defined therebetween, and an annular output hydraulic chamber 3 surrounding the booster piston 35 is defined between the large diameter piston portion 35a and the rear end wall of the booster cylinder 32.
8 is defined. Therefore, the input hydraulic chamber 37 and the output hydraulic chamber 38 are arranged facing both sides of the large diameter piston portion 35a of the booster piston 35, but the pressure receiving area facing the output hydraulic chamber 38 of the booster piston 35 is the input hydraulic chamber. It is set larger than the pressure receiving area facing 37.

An outlet chamber 39 is defined between the large diameter piston portion 8b of the rear master piston 8 of the master cylinder M and the small diameter piston portion 35b of the booster piston 35. Also, the rear end of the cylinder body I and the booster cylinder 3
An annular oil passage 40 is formed between the guide ring 31 and the groove 4 radially provided on the front end surface of the guide ring 31.
1 to an outlet chamber 39. Furthermore, a connecting pipe 42 communicating with an annular oil passage 40 is connected to the booster cylinder 32, and this connecting pipe 42 is connected to the oil tank 2 or an oil tank of a hydraulic pressure supply source (not shown) via a pipe line (not shown). Therefore, the outlet chamber 39 communicates with the oil tank 2 or the oil tank of a hydraulic pressure supply source (not shown).

A supply oil passage 43 communicating with the input hydraulic pressure chamber 37 is bored in the booster cylinder 32, and this supply oil passage 43 includes:
A hydraulic power supply source (not shown) that pumps hydraulic oil from the oil tank 2 or an oil tank (not shown) is connected.

An output rod 44 is fixed to the front end of the booster piston 35, and this output rod 44 is connected to the rear master piston 8.
The piston 8 enters the recess 45 provided on the back surface of the piston 8.
is brought into contact with.

A basically cylindrical guide member 46 is held between the output power rod 44 and the booster piston 35, and the output hydraulic chamber 3 is located between the guide member 46 and the booster piston 35.
An oil chamber 47 communicating with 8 is formed. an input hydraulic chamber 37;
The guide member 46 is provided with a plurality of inlet valves 48 so as to be able to communicate with an oil chamber 47 communicating with the output hydraulic chamber 38 .

These inlet valves 48 are connected to the input hydraulic chamber 37 and the oil chamber 47.
a cylindrical valve chamber 50 formed in the guide member 46 along the axial direction of the booster piston 35 in the middle of the oil passage 49 connecting the
A spherical valve element 51 opens and closes the oil passage 49 in cooperation with a valve seat formed on the rear end wall of the valve chamber 50, and a valve accommodated in the valve chamber 50 to bias the valve element 51 toward the closing side. It is constructed in a normally closed type by a spring 52 and an operating rod 53 for pressing the valve body 51 toward the opening side against the spring force of the valve spring 52. Furthermore, the operating rod 53 is fitted into the guide member 46 so as to be freely movable in the axial direction, and its rear end protrudes into the oil chamber 47 . Further, the amount of protrusion of each operating rod 53 into the oil chamber 47 is set to be slightly different.

A guide hole 54 is coaxially bored in the rod portion 35c of the booster piston 35 extending from the rear end to the oil chamber 47, and a guide hole 54 is formed coaxially with the rod portion 35c of the booster piston 35 from the rear end to the oil chamber 47. Also, a small diameter sliding hole 55 is bored. A valve piston 56 is inserted into the guide hole 54 of the booster piston 35, and the front part of the valve piston 56 is connected to the sliding hole 5.
5 is slidably fitted. On the other hand, the rod portion 35c
A pair of oil holes 57 are bored at the base end of the booster piston 35 along one diameter line of the booster piston 35 to communicate the oil chamber 47 with the output hydraulic pressure chamber 38 through the guide hole 54. A pin 58 that protrudes from the hole 57 into the output hydraulic chamber 38 is screwed together perpendicular to the axis. Between the oil chamber 47 and the guide hole 54 is a cylindrical interlocking member 5 that surrounds the valve piston 56 and has its rear end abutted against the bottle 58.
9 is arranged, and the tip of this interlocking member 59 is formed so as to be able to come into contact with the rear end of the operating rod 53 in each artificial valve 48. Moreover, a spring 60 is interposed between the guide member 46 and the interlocking member 59, and this spring 60 causes the interlocking member to
The rear end of the pin 9 is always in contact with the pin 5. Therefore, the inlet valve 4 is driven to open and close according to the axial relative movement of the pin 58, that is, the valve piston 56, with respect to the booster piston 35. The booster piston 35 is formed to be long in the axial direction to allow relative axial movement within a limited range.

The valve piston 56 is coaxially formed with a passage 61 that opens on its front end surface, and the output rod 44 has a passage 61 coaxially bored therein to communicate the passage 61 with the outlet chamber 39, that is, the oil tank 2 or the oil tank of a hydraulic pressure supply source (not shown). A communication hole 62 is bored. A valve hole 63 communicating with the front end of the passage 61 at right angles is connected to the valve piston 5.
6, and this valve hole 63 can be switched between a state in which it is closed by the guide member 46 and a state in which it communicates with the oil chamber 47, depending on the relative position of the valve piston 56 in the axial direction with respect to the booster piston 35. The outlet valve 64 is thus configured. Moreover, the outlet valve 64 is slightly opened when the booster piston 35 is at the retraction limit and the valve piston 56 is also at the retraction limit, and the outlet valve 64 is opened slightly as the valve piston 56 moves forward from that state. The valve is arranged so that the valve is closed.

A bushing rod 65 as an operating member is connected to the rear end of the valve piston 56, and the bushing rod 5 is linked and connected to a brake pedal (not shown). As a result, the valve piston 5 responds to the depression of the brake pedal.
6 operates forward.

A stopper 66 that can support the bottle 58 from the rear is locked on the inner wall of the booster cylinder 32, and when the booster piston 35 is at its retraction limit, the stopper 66 causes the pin 58, that is, the valve piston 56 to reach its retraction limit. 66.

Also, during the retraction process of the booster piston 35, the valve piston 56
In order to limit the retraction limit of the valve piston 56, a stopper 67 that can come into contact with the rear end of the valve piston 56 is engaged with a circlip 68 fitted on the inner surface of the rod portion 35c near the rear end.

Therefore, when the valve piston 56 is retracted, the outlet valve 64 is opened, and when the valve piston 56 is stopped by the stopper 66 at the retracting limit of the booster piston 35, the opening of the outlet valve 64 is changed. is the minimum.

, the rear end of the booster piston 35, that is, the rod portion 35
A reaction mechanism R for transmitting the operational reaction force of the master cylinder M to the valve piston 56 is provided between the rear end portion of the valve piston 56 and the rear end portion of the valve piston 56 . This reaction mechanism R includes a cylindrical support that surrounds the valve piston 56 and is supported by the rod portion 35c, a member 69, and a flange that is integrally provided at the rear end of the valve piston 56 and extends outward in the radial direction. The receiver is made up of a transmission member 71 supported by member 69 so as to be able to come into contact with portion 70 . The receiving member 69 has its front end supported by a retaining ring 72 fitted to the inner surface of the guide hole 54 at a portion corresponding to the rear end edge of the oil hole 57 provided in the rod portion 35c, and is connected to the valve piston 56 and the rod portion 35c. The intermediate portion of the valve piston 56 is supported by a member 69 in this receiver. Moreover, the guide hole 54
A seal member 73 that contacts the inner surface of the receiver member 69 is attached to the outer surface of the receiver member 69, and a seal member 74 that comes into sliding contact with the inner surface of the receiver member 69 is attached to the outer surface of the valve piston 56. Further, the transmission member 71 is formed in a cylindrical shape, and is disposed between the rod portion 35c and the valve piston 56 so that its front end is brought into contact with the rear end of the receiving member 69. Moreover, the transmission member 71
A transmission member 71 is placed between the stopper 67 and the receiving member 69.
A spring 75 is interposed to exert a spring force in the direction of bringing the stopper 67 into contact with the circlip 6.
Abuts on and is supported by 8.

Next, the operation of this embodiment will be explained. When the brake pedal (not shown) is not operated, the valve piston 56 is held at the retracting limit together with the interlocking member 59 by the spring force of the spring 60, and the booster piston 35 is It is held at the backward limit by the hydraulic pressure acting on it. Moreover, in this state, the inlet valve 48 is closed and the Yamaguchi valve 64 is slightly opened, so the output hydraulic pressure chamber 38 is at atmospheric pressure.

In this state, when the brake pedal is depressed to brake the automobile, the valve piston 56 and the interlocking member 59 are pushed forward from the brake pedal via the bushing rod 65, and the outlet valve 64 is closed first, and then the inlet valve is closed. 48 opens. Therefore, oil pressure is introduced into the output oil pressure chamber 38 from the input oil pressure chamber 37 . As a result, the booster piston 35 receives hydraulic pressure on its rear end face and moves forward, causing the rear master piston 8 to move forward via the output rod 44, and the master piston M
boost operation is started.

By the way, at the beginning of the forward movement of the booster piston 35,
Since the flange 70 does not contact the transmission member 71, the operating wave force from the master cylinder M does not act on the valve piston 56 and the bushing rod 65, and the output rod 44 does not touch the bushing rod 6.
It advances regardless of the value of the input from 5, and the master cylinder M
The output oil pressure from the pump rises rapidly as shown by characteristic lines P and -P in FIG. This immediately eliminates any play up to the brake terminal.

After the flange 70 comes into contact with the transmission member 71, the operational reaction force from the booster piston 35 is transmitted to the bushing rod 65, and from then on, the characteristic line P+P in FIG.
As shown by g, the amount of movement of the booster piston 35, that is, the output oil pressure from the master cylinder M increases at a constant rate.

Point P in Figure 3! is the boosting limit point of the hydraulic booster B, and the increase in output after that point depends only on the input as shown by the characteristic lines P and -P.

When the brake pedal is released to deactivate the master cylinder M, the valve piston 56 moves back together with the interlocking member 59 due to the elastic force of the spring 60.

Accordingly, the interlocking member 59 first separates from the operating rod 53, the inlet valve 48 closes, and then the outlet valve 64 opens. When the opening degree of the output valve 64 reaches the maximum, the valve piston 5
6 is restricted from retracting by a stopper 67.

By opening the outlet valve 64 to the maximum opening degree in this manner, the hydraulic pressure in the output hydraulic pressure chamber 38 is quickly discharged, and the booster piston 35 is activated by the return springs 12 and 13 of the master cylinder M.
It quickly retreats due to the return force such as. When the booster piston 35 reaches the retraction limit where it comes into contact with the stepped portion 36, the valve piston 56 is regulated by the stopper 66 and stops at a position further forward relative to the booster piston 35 than when it was regulated by the stopper 67. As a result, the exit valve 6
The opening degree of 4 is the minimum.

In this hydraulic booster B, the reaction mechanism R is disposed between the rear end of the booster piston 35 and the rear end of the valve piston 56, that is, at the rear end of the hydraulic booster B. Therefore, the reaction mechanism R can be placed in a position that is unrelated to the complicated structure of the inlet valve 48, the outlet valve 64, etc., and the structure of the reaction mechanism R can be simplified, making it easier to process. becomes.

C1 Effects of the Invention As described above, according to the present invention, the reaction mechanism is provided between the booster piston and the valve piston near the rear end of the booster piston, which simplifies the structure of the reaction mechanism and facilitates machining. In addition, the degree of freedom in the structure of the reaction mechanism is increased.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional side view, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. 3 is a human power-output hydraulic characteristic diagram. 8... Master piston, 32... Booster cylinder, 35... Booster piston, 37... Input hydraulic chamber, 38... Output hydraulic chamber, 39... Outlet chamber, 44...
・Output rod, 48... Inlet valve, 56... Valve piston,
64... Outlet valve, 65... Push rod as operating member, B... Hydraulic booster, M... Master cylinder, R... Recoil mechanism

Claims (1)

[Claims] A booster piston, which has an output rod at its tip that comes into contact with the rear end of the master piston that is slidably fitted into the master cylinder, is slidably fitted into the booster cylinder that is connected to the rear end of the master cylinder. A valve piston connected to an operating member and inserted into the booster piston so as to be movable in the axial direction is connected to the booster piston between the output hydraulic chamber formed facing the back of the piston and the input hydraulic chamber communicating with the hydraulic pressure supply source. An inlet valve that opens in response to forward motion is interposed, and an outlet valve that closes in response to forward motion of the valve piston relative to the booster piston is interposed between the output hydraulic chamber and the outlet chamber communicating with the oil tank. In a hydraulic booster, a reaction mechanism is provided between the booster piston and the valve piston to transmit the operating reaction force of the output rod to the valve piston. A hydraulic booster characterized in that it is provided in.